Clinical Comparison of an Echocardiograph-Derived Versus Pulse Counter–Derived Cardiac Output Measurement in Abdominal Aortic Aneurysm Surgery

ObjectiveTo compare cardiac output (CO) measurements acquired using the Flotrac/Vigileo system (Edwards Lifesciences, Irvine, CA) and CO measured by transesophageal echocardiography using the product of the aortic valve area, the time integral of flow at the same site, and the heart rate during abdominal aortic aneurysm (AAA) surgery.DesignA prospective clinical study.SettingCardiac surgery operating room of 1 heart center hospital.ParticipantsTwenty patients undergoing elective AAA surgery.InterventionsCO was determined simultaneously using the Flotrac/Vigileo system (COAP) and transesophageal echocardiography (COTEE) as the reference method at 8 time points during AAA surgery.Measurements and Main ResultsOne hundred sixty simultaneous datasets were obtained. The authors observed a significant correlation between COAP and COTEE values (R = 0.56, p < 0.001). Bland-Altman analysis of COAP and COTEE showed a bias of 0.12 L/min and limits of agreement from −1.66 to 1.90 L/min, with a percentage error of 41%. Just after aortic clamping, COAP significantly increased, but COTEE decreased in comparison with previous measurements. There was a significant association among changes in COAP and pulse pressure, heart rate, and central venous pressure (CVP). However, changes in COTEE were only associated with variations in heart rate.ConclusionsCOAP values were not clinically acceptable for use in AAA surgery because of wide variations during aortic clamping and declamping. Changes in pulse pressure, heart rate, and CVP were associated with significant changes in COAP, whereas only changes in heart rate showed associated changes in COTEE.